Printing machine



3 o 1641100 Aug 1927 D. J. SCOTT PRINTING MACHINE Filed Feb.4. 192s 2 Shee ts-Sheet 1 gvweuto'c WWW 1,641,100 Aug. 1927 D. J. SCOTT PRINTING MACHINE avvoemtoz I a tented Aug. 30, 19 27.

UNITED STATES r, 1,641,100 PATENT OFFICE.

DAVID SCOTT, OF PLAINFIELD, NEW JERSEY, AS SIGNOR TO ISABELLA SCOTT AND DAVID J. SCOTT EXIECUTOBS OF THE ESTATE OF WALTER SCOTT, DECEASED, DOING BUSINESS UNDER THE NAME OF WALTER SCOTT 8c COMPANY, OF PLAINFIELD,

NEW JERSEY.

PRINTING MACHINE.

Application filed February 4, 1926. Serial 1W. 85,819.

This invention relates to printing machines, and has for its main object and feature the provision of means associated with two printing couples, one for printing and 6 the other for perfecting a web, whereby a web can be successfully printed atwill by either couple first.

In the art of rinting, as practiced at the present time, it is customary to drive one of the cylinders of a printing couple from a drive shaft and to drive not'only the other cylinder of the couple from the first one but also to drive the cylinders of the second couple from the cylinders of the first couple.

l5 Owing to the fact that it is impossible to avoid backlash in the gears and that the effect of this backlash is cumulative, that is, the greater the number of gears the greater the effect, it will be understood that, in a construction where one cou 1e is driven from another, the pull of the cy inders of the different cou Ice is not equal. As a consequence, it as been the practice to lead the web to be printed and perfected first to the couple that is nearest the driving shaft and then to the couple more remote from the driving shaft; that is, the web passes first to the cou 1e exerting the greater pull or having the east backlash and then to the couple exerting the lesser pull or having the greater backlash. If the web is always threaded through the couples in the order named, satisfactory printing will be accomplished because the couple exerting the greater pull is drawing from a web roll that responds to the pull of the cylinders. If, however, it is now attempted to thread the web in the reverse order, that is: first through the cylinders exerting the lesser pull and then through the cylinders exertlng the greater pull, then the web is apt to break because of the unyielding character of the paper feed of the cylinders exerting the lesser 1111 and the no less unyielding character of ti: 4.6 feed of the cylinders exerting the greater pull, or, if the web does not break but is pulled bodily between the cylinders exerting the lesser pull then the printing becomes smeared. It will therefore be seen that, if the gearing can be so arranged that either printing couple exerts substantially the same ull, it is immaterial how the web is threaded. In printing from type it is usually of no consequence which side of the e paper paper is printed first, but in printing from half-tone or Ben Da plates it has been found that one side 0 the paper, especially news-print paper, will receive a better impression than the bther. It is therefore not only a great convenience to be able to thread the paper in different ways, but it likewise improves the. quality of. the printing and is therefore highly desirable in every way.

Accordingly the invention consists in providing means whereby the two printin coupies can be so driven as to exert su stantially an equal pull. on the web and in the other features of construction hereinafter disclosed in a preferred embodiment in the drawings in which:

Fig. 1 is a diagrammatic view of two printing couples and associated elements shpiwing the web threaded in one direction, an

Fig. 2 is a diagrammatic View similar to Fig. 1 showing the web threaded in the other direction.

1 and 2 indicate two printing couples each consisting here of two cylinders designated by 3, 4, 5 and 6. 7 indicates a horizontal driving shaft and 8 and 9 are two vertical shafts. Separate gearing is arranged between the horizontal shaft and thetwo vertical shafts here taking the form of bevel gears 10, 11 and 12, 13. Vertical shaft 8 drives printing couple 1 by means of bevel gears 14 and 15, and vertical shaft 9 drives printing couple 2 by means of bevel gears Spur gears 19 and 20 interconnect the cyl-'- inders of the two couples but it will be un derstood that these gears in nowise defeat the advantage of the separate drives; their object is to prevent the two couples from becoming circumferentiall displaced or out of time in case one coup e is disconnected from its driving means. If while such coupie is disconnected it should be attempted to gearing for driving one couple from one turn it the other couple would likewise be vertical shaft and the other couple from the turned. other vertical shaft, and gearing directl I claim: connecting the cou les aforesaid, independ I A printing mechanism including: two ently of the vertica shafts, to maintain their 15 printing couples, one for printing and the circumferentially timed relation. other for perfecting a web, a horizontaltiiy Signed at Plainfield, in the county of Undisposed drive shaft, twowerticaily exten ion and State of New Jersey this 28th day ing shafts, independent gearing connecting of January, 1926.

10 the drive shaft with each vertical shaft, DAVID J. SCOTT. 

